Limited type matching?

[Namespace]

On Tuesday, 10 September 2013 at 10:53:15 UTC, Kenji Hara wrote:
> On Tuesday, 10 September 2013 at 08:04:48 UTC, Namespace wrote:
>>> Currently, all of array types does not allow copy-conversion 
>>> like ushort to short for their elements.
>>>
>>> In old D1 age, static array did not have value semantics, so 
>>> the behavior was expected.
>>> In D2, static array had changed to value type, but the 
>>> behavior was not changed.
>>>
>>> As far as I know, there was no discussion about that, but at 
>>> least it is not fundamentally wrong.
>>>
>>> Kenji Hara
>>
>> And what is your personal opinion?
>> I think an implicit cast between signed / unsigned would be 
>> acceptable even with static arrays. It were only logical.
>
> Hmm, OK. I've taken a look a little deeper about the current 
> behavior.
>
> void main()
> {
>     void f1(short) {}
>     void f2(short[2]) {}
>     void f3(short[]) {}
>
>     ushort us = 1;
>     short ss = us;      // OK
>     ss = us;            // OK
>     f1(us);             // OK
>
>     ushort[2] usa = [1,2];
>     short[2] ssa = usa; // OK -> [x]
>     ssa = usa;          // NG -> [y]
>     f2(usa);            // NG -> [y]
>
>     ushort[] uda = [1,2];
>     short[] sda = uda;  // NG, expected
>     sda = uda;          // NG, expected
>     f3(uda);            // NG, expected
> }
>
> Surely the current state that, [x] is accepted but [y] is 
> rejected, looks weird to me. It would be a bug.
>
> Kenji Hara

Nice to hear. I already filled a bug report: 
http://d.puremagic.com/issues/show_bug.cgi?id=10999